Project Summary Significance: Despite decades of effort, several racial and ethnic groups are underrepresented in science compared with their proportion of the general population. In part, this disparity is due to a higher rate of attrition from biomedical training pathways for scientists from underrepresented (UR) groups. As a scientific society, the American Society for Cell Biology (ASCB) recognizes the particular stability that societies can provide scientists as they transition across career stage and institutions. Among the many efforts to increase retention for UR scientists, the academic institutions that have seen a lasting increase in retention employed both a transformation of institutional culture to make it more inclusive and support programs that deliver mentoring and training to the UR scientists. Proposed Action: ASCB will adapt this successful approach as a model for how a scientific society can increase retention of UR scientists in biomedical training, increasing diversity in science and reducing the disparity in representation. Specific Aims: The activities in Aim 1 initiate a change in institutional culture toward inclusion through an inclusiveness workshop for ASCB leadership, diversity and inclusion training for general members at the Annual Meeting, and a new poster session and keynote speaker on the Scholarship of Diversity to signal to the membership that diversity is relevant for all members. In Aim 2, grad students, postdocs, and junior faculty at risk for lower-than-usual mentoring will be selected for a multi- year program that offers extensive multi-level mentoring and community, professional development and bioinformatics training, and a practicum in which to practice the new skills in a supported environment. Aim 3 takes advantage of the large Annual Meeting to offer activities that increase the rate of interaction among UR and majority scientists, as well as deliver mentoring and training to emerging scientists. These activities include a travel awards program to bring UR undergraduates, grad students, postdocs, and junior faculty to the Annual Meeting, professional development and multiple structured mentoring opportunities for these emerging scientists, a separate poster competition for networking and practice ahead of the general session, a major session to highlight spectacular research from a UR scientist, and a major session to recognize the importance of mentoring and see an example of its impact. Although the funding length is too short to directly measure the impact of the activities on retention in biomedical training, this proposal identifies measures that are acceptable proxies for the likelihood of remaining in biomedical training. To judge impact, pre- and post-program metrics will be gathered, and the changes in the participant group will be compared with an otherwise-similar group of non-participants. Overall impact: All told, these activities are expected to impact 1000+ participants annually through a combination of activities that adapt best practices in academia to the needs and strengths of a scientific society, testing a multi-prong model for how a society can have a lasting impact on diversity.